Summary The main objective of the Animal Metabolic Physiology Core is to provide teaching and consultation on experimental design, performance of techniques, and analysis and interpretation of data for in vivo and ex vivo methods to investigate alterations of glucose homeostasis, insulin action, leptin action and body composition in rodent models of obesity and insulin resistance. Increasingly, the biologic roles of gene products and pathways emerging from genomic, proteomic, metabolomic and other discovery approaches are being queried by generating overexpression and gene knockout rodent models. Thus, there is a growing need for characterization of new mouse models created by genetic or viral vector technologies. The Animal Metabolic Physiology Core is designed to meet the needs for characterization of rodent models that have alterations in glucose homeostasis, insulin action, leptin action and/or body composition and adiposity. The consultation is carried out with an emphasis on the translational aspects of the studies. The specific objectives of the Core are 1) to teach and 2) to provide consultation to investigators in designing, carrying out and interpreting in vivo, ex vivo, and in vitro studies aimed at investigating glucose homeostasis; lipid metabolism; insulin action; the actions of other hormones that regulate insulin sensitivity and energy balance such as leptin; and body composition 3) to review the results with users and assist in analysis and interpretation to ensure accuracy of results and understanding of their biological meaning. The Core also performs a limited number of these studies on selected mouse or rat models obtained by members of the Center.